Ecobee smart thermostat -- so, I got one (with some pics and a portscan)

Ars's review of the Ecobee thermostat back in October left me intrigued and interested--the idea of a thermostat I could control via a web interface was very appealing to me. I was in the market for a new thermostat anyway, one with the ability to do different things for different days of the week, and my current thermostat (a Carrier Flatstat) couldn't keep accurate time and its clock would lose 80-90 minutes a day, making it basically worthless as anything other than a dumb thermostat.

I exchanged some e-mails with the Ecobee folks, and when they let me know that their product was for sale last Monday, I purchased one. It was $385, with non-express shipping from Canada costing $20 and next-day air shipping costing $25, so at 09:00 on Tuesday morning I was holding my new thermostat in my hands.

InstallationThe package didn't just contain a thermostat--it had a thermostat and an "equipment interface module". Unless you're an HVAC technician, you'll likely need professional help installing the thing. I called the service company that installed my home's AC & heating gear when it was built a few years ago, and they sent out a guy to take care of the work.

The installer (his name was Les) commented on arriving that he'd never heard of the brand before and wasn't sure if he could actually connect it, but fortunately the thing comes with an installation guide that includes wiring diagrams. Les powered the system down, pulled the old Carrier thermostat from the wall, and then took the guide and the equipment interface module and disappeared into my attic for about ten minutes. He returned and noted that it was actually easier to plug in than he had anticipated.

Here's the EIM, mounted on my air handler in my attic. Easily visible are the wires that Les had to run from the AHU to the EIM.

A bit further back. Not sure what that orange stuff is, but it's been there since we moved in and it's rock-solid, so it's not hurting anything. Visible are the two sets of wires going into the AHU and the black power cable, running from the EIM to a wall-wart that plugs into a standard electrical outlet.

View from the attic door looking over at the EIM mounting on the AHU.

Les then helped me attach the wall unit to the wall. My old thermostat sat flush with the wall, with its guts nestled into a box; the ecobee wall unit has a backplate that screws into the wall, and then it mounts onto the backplate. Because the backplate was of different dimensions than the old thermostat, I had to screw a switch plate into the wall to cover the otherwise-visible hole. The resulting mount job looks like this:

The wall unit uses a standard four-wire setup, and was quite literally plug-and-play (especially since Les had done all the wiring stuff in the attic already). Upon being plugged in, it booted up to its home screen. Since at that point Les & I both were in uncharted territory, we entered into the thermostat's technician screens and found the installation wizard. It asked about the number and types of HVAC equipment to which it was connected, as well as several other things that I didn't understand but Les assured me were fairly standard HVAC questions, then the wizard concluded with a picture of its proposed EIM wiring diagram, based on the answers we'd given the wizard:

(I had to scroll between the two pictures)

There are actually hookups for all kinds of HVAC configurations, as well as accessory gear like detectors and relays that I don't have. I took pictures of a few of the screens in the installer menu:

Les left me at this point, and I ran through the rest of the setup on my own. The thermostat picked up my wireless access point and accepted my WPA2 password without incident, pulling itself an address from my DHCP pool and connecting to ecobee's web site with no problems. I had some minor trouble walking through their account set-up tool (their page ate my info on the first registration attempt), but I was successfully talking to my thermostat via their web portal about ten minutes after the installer was done:

I also punched in the installer's information so it would be registered in the unit and set up the reminders for filter changes and inspections, so it would e-mail me when those were due. Which is good, because I can never remember to change my damn air filters on time.

Look-n-feelHaving been spoiled by the iPhone, it's a little disappointing that the touchscreen on this nearly four-hundred dollar device is resistive instead of capacitive. It feels squishy, like an old-school Palm Pilot screen. Touches are not nearly as accurate as I'd like them to be, and fine work (like sliding the thermostat "dial" up or down by one degree) is sometimes frustrating as the control being manipulated jiggles and jerks somewhat, seemingly wanting to go everywhere other than where you set it. Soft touches don't register all the time; fingernail taps seem to work the best. A stylus would probably work best, though the device doesn't come with one.

The entire interface feels like it was designed by someone holding an iPhone in one hand and drawing with the other one. Configuration menu items resemble iPhone-style nested menus. Scrolling is done iPhone-style, with some programming effort spared to give the menus a sense of inertia, though the effect is neither smooth nor consistent.

The web interface is functional, but also lacks consistency between widget. The most egregious example is that daily settings can be adjusted with drag handles (so, for example, to make your "stay at home" event last longer or be warmer or colder, you can drag the event's shape around on its various axes), but the weekly program events cannot; dragging within that widget creates new events instead. The weather widget only updates once a day and, at least for my location, displays incorrect information (the temp shown is at least ten degrees colder than reality). Ecobee is aware of the temp display issues and promises to fix a lot of the issues with an update coming next week.

Day to day usageI'm quite happy with how the thing works day to day. The thermostat has another wizard that you can run to tell it when you wake up, when you go to work, when you come home, and when you go to sleep, and what temperature ranges you want it to keep during each of those periods. You can adjust settings per day, or in groups of days. I work from home on Wednesdays, so constructed a schedule that fits with me and my wife's work schedules in a few seconds.

From either the thermostat or the web, I can make adjustments to just today's program, change the entire week's program, or pause the program and explicitly set the temperature to whatever I want. There's also a "quick save" button I can press when I leave the house, which puts the system into energy saving mode regardless of what part of the program is currently active. The vacation mode lets you block out days where you'll be out of town (including, I was happy to see, what time you leave and return, so the thermostat won't set itself to energy saving mode on the morning of the day your your evening flight is scheduled).

Since last Tuesday, I find myself ignoring the thermostat a lot more than I used to be able to do. I've got the program dialed in to some approximation of the manual routine my wife and I had been using for the past four years, and so far it's going quite smoothly. It's actually slightly disappointing--here I am with a new gadget, and once it was set up, there wasn't much playing I could do with it.

If there is an annoyance about the thing, it's that either it's slightly off on how it measures indoor temperatures, or my old thermostat was slightly off; 72 degrees doesn't feel the same now as it did with the old thermostat. I've used the offset control in the technician menu to adjust it as well as I can, including using a handheld digital thermometer to make sure it's as correct as I can make it (it needed to be adjusted down by 1.5 degrees F to read the same as the thermometer, which definitely makes the house feel closer in temperature to the old unit, but not quite). I am still tweaking where I want the settings, but the weather is so mild in Houston right now that it honestly hasn't had to run very much. As we get out of "winter" and into summer--which immediately follows winter around here, since we have no spring--I'm sure it will get much more of a workout.

Behind the scenesRight, so, no wifi device gets on my network without a thorough port scanning.

Several more thorough scans reveal nothing else interesting happening--those are the only listening ports. It appears to be running some flavor of Linux, which is kind of exciting, because that means at least the potential for hacking is there. Attempting to connect to the FTP service yields this:

I can't give it an anonymous password that it will accept, and a quick runthrough of common username/password combinations for a non-anonymous logon yields no hits. I'm not sure what the FTP server would be good for; I've opened no firewall holes for it and I have uPnP disabled. The box appears to be talking back to the mothership via a single persistent TCP connection from local port 4162 to 216.220.61.236:8089:

Finally, attempting to connect to the tcpwrapped port 23 yields no results, since I'm obviously not on the tcpwrapper ACL. Again, though, I'm not sure what good it does being there, since there's no way for anything external to my LAN to get to it.

ConclusionsI'm basically happy with the thing. It was expensive, but so far it does what it says on the tin, which is all we can hope for in any piece of consumer electronics. At least it wasn't one of these. There are some interface issues and inconsistencies, but on the whole the thing is easy for me to use. More importantly, it passes the wife test--she has no problem temporarily overriding the temperatures when she's too cold (which is basically all the time), so she's happy with it. No word yet on whether or not it's actually saving me money on my utilities, since this is the cheapest part of the year to keep a house comfortable. I'll know much more about that come August and September, when I'm usually spending $250 a month on electricity.

I'm trying to understand why you would need an HVAC tech to do the EIM. It uses the same wires that go to your thermostat, just spliced in between the HVAC and the thermostat. You could have mounted it on the wall right next to the thermostat if you wanted. Or am I missing something?

Originally posted by travathian:I'm trying to understand why you would need an HVAC tech to do the EIM. It uses the same wires that go to your thermostat, just spliced in between the HVAC and the thermostat. You could have mounted it on the wall right next to the thermostat if you wanted. Or am I missing something?

I probably could have, if I'd any confidence at all in my ability to do so. Which I totally don't. I read the install manual, and when they were talking about running wires, I put it right down and called an installer.

edited to add -- I think you're missing something. The wiring diagram shows three wires going to the EIM (Y, W O/B, and G), which then spits out four wires (D-, D+, 12 volt, and ground) which to go the thermostat on the wall.

So it doesn't appear to be quite as simple as just splicing the thing in. I know next to nothing about HVAC gear, but it's clear that the EIM is adding something to the mix.

Thanks for the write up. Interesting product. I like the idea of being able to check on my place while away on vacation (no burst pipes in winter, etc.).

If it could control my humidifier, I'd add it to the list of things to buy after the recession

quote:

The wiring diagram shows three wires going to the EIM (Y, W O/B, and G), which then spits out four wires (D-, D+, 12 volt, and ground) which to go the thermostat on the wall.

I'm guessing the first 4 wires are the standard thermostat wires that the EIM talks to the air handler with. D- And D+ is likely data, with the rest being power of course for the wall unit. Since there were already 4 wires form the old thermostat to the air handler, you designate which color become the D+, D-, etc. and just re-purpose them.

Originally posted by travathian:So an extra $300 gets you a web interface and a touch screen? Yeouch.

You're evaluating it purely on a "what do I get" basis without taking into account economies of scale. This is a somewhat bleeding edge and definitely not mass market product, so naturally it's going to be pricey. If you think it's cool then you should thank Pokrface for being an early adopter and thus (hopefully) helping to bring the prices down for the rest of us.

If it could control my humidifier, I'd add it to the list of things to buy after the recession

It's got a screen for humidifier control, yep (see the picture of the web interface in the OP). I don't have one, since the Texas gulf coast is about the last place in the world where you need extra humidity, but the device can interface with your humidifier.

edited to add -- I think you're missing something. The wiring diagram shows three wires going to the EIM (Y, W O/B, and G), which then spits out four wires (D-, D+, 12 volt, and ground) which to go the thermostat on the wall.

So it doesn't appear to be quite as simple as just splicing the thing in. I know next to nothing about HVAC gear, but it's clear that the EIM is adding something to the mix.

All HVAC equipment uses a standard of wiring, using 24VAC signalling. R (or in dual transformer systems RH for heat and RC for cool) is a 24VAC source that gets connected to various other terminals to turn things on. G for the fan, W for heat, Y for cool (and various others depending on your setup like O for the reversing valve in a heatpump setup)

The 4 wires going to the wall unit are more or less like a USB bus, and have no relation to the HVAC side of the module, two data lines and power and ground. The EIM then connects R to the various other outputs depending on what the system calls for, for example in cooling, generally R is tied to Y and G.

If you ever have a thermostat die and you need heat/cool you can just twist the wires you want together, R is generally Red, Fan (G) is green, W is for heat and is usually white, and cool is Y, which is Yellow/Blue depending on the wiring.

So, what does this really practically do for you over a standard touch screen thermostat? I got one from Lowes for $40 on sale. I can set four temperature changes per day, and each day can have it's own schedule and temperatures. I generally set it to go down to 50 degrees while I'm at work and to comeback up to 68 when I get home. It also drops the temperature to 62 when I'm in bed.

The only problem of course is that it's in the room with my computers, so I have to fudge the temperatures to get it to be comfortable in the rest of my apartment.

Running Linux on this thing is totally believable. If you look it up on the FCC, you can get cool internal photos without taking yours apart! It's FCCID WR9EBSTAT.

Page 11 of the internal photos has a very standard embedded device layout going on: the two identical chips at the top are RAM, the Samsung chip to the right (by the battery) is flash, and there is what appears to be a Samsung? processor, probably an ARM In the top-right corner is U17, which is probably the thermostate, given that it's isolated-ish from the rest of the board. One of the other documents has a picture of the Wifi module (which is the IC in the bottom right corner on the back side of the board, pg 10), a Wi2Wi W2SW0001. Looking at the datasheet, it supports Linux on many ARM processors. Since the processor we have is definitely not a Marvell (no stylized M which you can see even in the worst of FCC photos ), it's probably running Linux or WinCE. Also, it's probably not running WinCE, because you'd be insane to do that these days Given the evidence, I'd say it runs Linux, so you should pull it open and get a serial console

sryan2k1: the four wires going from the interface module to the thermostat are almost certainly a USB-like thing, if not USB. The wires from the silkscreen in the photos are +12V, GND, D+, and D-.

edit:Pokrface: look at page 13 of the photos. The EIM is basically a bunch of relays controlled by a microcontroller of some sort. That way the large number of wires and any high-current stuff stays at the EIM, and only the low-voltage communcation stuff goes to the thermostat. (Relays are the 7 big black boxes, the square with legs on all sides below them is the microcontroller, and then four guys with legs off to the left of that are probably for controlling the relays).

That's a nice looking screen, but without more connectivity and needing to rely on an outside subscription service, they seem limited to me.

I've got a couple TR40s running on an RS-485 interface. They are linked into my control panel, which isn't a trivial expense, but it also serves as alarm and automation for lighting and other things. I can monitor the thermostats and set them remotely by phone or computer. I can also change them through a set of routines I programmed into the controller as well as trigger events based on the thermostats. I had a thermostat call me at 2am and tell me it was more than 5F below set point. Obviously, the furnace had gone out. They also change set points based on outside weather and work pretty well for automated switching from heat to cool modes.

Hasn't anyone heard of Proliphix? As far as I know they were the first to sell a web stat. I've had mine (NT10e) for about 2 years and it works great and was a lot less cumbersome to install and configure than what you reviewed here. However, I will say the LCD is more like a standard programmable stat with no color or touchscreen, but that makes it more familiar for my better half.

I bought mine for a second home and it sends me email or SMS alarms for high temp, low temp and a filter change reminder! It even has a "failsafe switch" which kicks on the heat if it drops below 50F and when there is no power to the stat.

There was no special HVAC wiring either. I just replaced my old programmbale with a one-for-one HVAC wire replacement. There was no EIM except I did have to run a Cat5 to the stat for power and data but it wasn't as difficult as what was described here (I didn't need to call anyone to help).

Although my model doesn't control humidity, I believe they do have a model that does.

But the best part is that there is no fee for the hosted service and the stat cost me less than $300. The hosted service also sends me emails when it looses conectivity to the stat. It happened twice and I learned that my cottage lost power and the other time, internet service.